The present invention relates generally to seat restraint systems for vehicles and, more particularly, to a tension sensing assembly for a seat restraint system in a vehicle.
It is known to provide a seat restraint system such as a seat belt in a vehicle to restrain an occupant in a seat of the vehicle. In some vehicles, the seat restraint system may be a lap belt, a shoulder belt, or both. Typically, the lap belt and shoulder belt are connected together at one end. The seat restraint system includes a latch plate at the connected end. The seat restraint system also includes a buckle connected at one end by webbing or the like to vehicle structure. The buckle receives the latch plate to be buckled together. When the buckle and latch plate are buckled together, the seat restraint system restrains movement of the occupant to help protect the occupant during a collision.
Smart inflatable restraint systems need to know what is occupying a seat of the vehicle. Decisions on deployment of inflatable restraints depend on information supplied by sensors in the seat in determining weight of an object in the seat. When a child seat is placed in the seat and cinched down, the sensors may read a large mass instead of a child seat. With this condition, there will be high tension in the seat restraint system. Comfort studies have shown that no human occupant would wear their seat restraint that tight. With this information on seat restraint tension, the inflatable restraint system can decide on deployment of the inflatable restraints.
Therefore, it is desirable to provide an assembly for sensing tension in a seat restraint system of a vehicle. It is also desirable to provide an assembly for sensing tension in a seat restraint system in a vehicle that allows a control module to decide on deployment of the inflatable restraints. It is further desirable to provide an assembly for sensing tension in a seat restraint system in a vehicle that mates with an existing buckle frame and provides an indication of high-tension forces in the seat restraint system. It is still further desirable to provide an assembly for sensing tension in a seat restraint system incorporating a cable attachment. Therefore, there is a need in the art to provide a tension sensing assembly that meets these desires.
It is, therefore, one object of the present invention to provide a new tension sensing assembly for sensing tension in a seat restraint system of a vehicle.
It is another object of the present invention to provide an assembly for tension sensing in a seat restraint system of a vehicle incorporating a cable attachment.
To achieve the foregoing objects, the present invention is a tension sensing assembly for a seat restraint system in a vehicle including a housing and a movable mechanism disposed in the housing. The tension sensing assembly also includes at least one spring disposed in the housing and cooperable with the movable mechanism. The tension sensing assembly includes at least one magnet disposed in the housing and a Hall effect sensor disposed in the housing and cooperable with the at least one magnet. The tension sensing assembly further includes a cable extending through the housing and cooperable with the movable mechanism to move the movable mechanism to deflect the at least one spring. The movable mechanism moves the at least one magnet relative to the Hall effect sensor to change an output of the Hall effect sensor to indicate a tension level in the seat restraint system when the at least one spring is deflected.
One advantage of the present invention is that a new tension sensing assembly is provided for a seat restraint system in a vehicle. Another advantage of the present invention is that the tension sensing assembly may be mounted on a buckle or inboard side of the vehicle or an anchor or outboard side of the vehicle. Yet another advantage of the present invention is that the tension sensing assembly may be packaged directly underneath a buckle assembly and is designed to mate with an existing buckle frame. Still another advantage of the present invention is that the tension sensing assembly incorporates a cable attachment to provide flexible presentation of the buckle assembly and allows for attachment to a pretensioner, if required. A further advantage of the present invention is that the tension sensing assembly incorporates a flexible cable to reduce bending moment due to inboard loading and allows the tension sensing assembly to stay in line with the buckle assembly. Yet a further advantage of the present invention is that the tension sensing assembly incorporates a boot that covers a portion of the buckle and the entire tension sensing assembly and can be attached with a snap or screw to the tension sensing assembly. Still a further advantage of the present invention is that the tension sensing assembly provides a reduction in overall package size and reduces the amount of parts.
Other objects, features, and advantages of the present invention will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.